As many other people have said better than I, being a professional is measured not just by the quality of your photos but also how you manage the business side of things. Being professional is handling client relations, billing, timeliness, attention to detail and most importantly - networking.

Expecting work to fall at your feet by just taking great photos is a myth. You have to be willing to seek out, continually, new work. That's the big step between hobbyist and pro.

Being a professional wedding photographer doesn't have any more or less professional aspects than someone who is a landscape or portrait photographer. Your viable option is to hustle. Hustle more to make more, less to bring in less.* Short of that you're a hobbyist.

*Momentum plays a big part here as well. If you get your name out there and have a steady stream of work it's hard to scale back when your interest wains if it's just a part time thing. It's hard to just do odd jobs. People won't immediately think to contact you if you're a "sometimes" photographer compared to someone who is known as a photographer. YMMV and all that.